Glycosyl flavonoids from the roots and rhizomes of Asarum longerhizomatosum.

Two new glycosyl flavonoids including a glycosyl aurone, together with six known flavonoids were isolated from the roots and rhizomes of Asarum longerhizomatosum. The structures of the two new compounds were elucidated as 4,6,4'-trihydroxy-aurone-4,6-di-O-beta-D-glucopyranoside (7, caulesauroneside) and naringenin-7,4'-di-O-beta-D-glucopyranoside (8, caulesnarinside). The six known flavonoids were identified as naringenin (1), naringenin-5-O-beta-D-glucopyranoside (2), naringenin-7-O-beta-D-glucopyranoside (3), chalcononaringenin-2'-O-beta-D-glucopyranoside (4), naringenin-5,7-di-O-beta-D-glucopyranoside (5), chalcononaringenin-2',4'-di-O-beta-D-glucopyranoside (6), respectively. This is the first report of the isolation of aurones in the family Aristolochiaceae.